No, I want to be able to vary the instruments' attack on individual notes. As you would know, stringed instruments can "ease into" a note and this is the preferred way of playing, generally. However, on fast notes this isn't really possible or, indeed, desirable. In the playback of my latest piece for strings, which has many sequences of repeated short notes (staccato quavers, semiquavers), they come back as a series of rapid pulsations which is pretty unpleasant. In fact - and I know it is asking too much - each note should have, as well as a rapid attack, a quick scratchy sound at the start.

I think the MIDI control I mentioned, if implemented, would give me what I want.

Now that I think a little more about it, I wonder if I can specify the value of the "attack rate" parameter ("ampeg_attack"?) as a function of the absolute length of the note (tempo times number of ticks), varying from zero for notes up to a certain length and then increasing proportionately up to the default full value for notes from a certain length and upwards.

The note decay rate should probably get the same treatment.

I will investigate but would be glad to read any suggestions you can make to help the process along.

In order to have the attack time change on key value you need to create regions, one for each of the 128 keys or - for simplicity - group them together. There is a parameter (ampeg_vel2attack) which can be used to set the attack as a function of the velocity, but there isn't one for key (this would be ampeg_key2attack). Anyhow, ampeg_vel2attack is not implemented in SynthFont.

Using SoundFonts this problem can easily be solved by using modulators.

Are you saying that I would have to put the parameter in each of the regions rather than under the group heading as I did? Actually, I did put it in the region of the test pitch I was using, still to no effect.

I would rather vary attack times with note length rather than velocity. There are many .sfz parameters but I think I couldn't find one to do this.